Model-based transmission acoustic analysis and improvement

A model-based transmission acoustic performance has been studied. Both excitation source and structure-borne noise transfer are investigated. For excitation source, transmission error is the main cause. To reduce transmission error, the most effective method is gear micro-geometry modification. However, there is no direct mathematical model that could reveal the relationship between transmission error and gear micro-geometry parameters, especially in the context of transmission system with shafts, bearings and housings included. By using multiple variable linear regression method, the relationship between transmission error and gear micro-geometry parameters is connected. The optimised transmission error decreases from 9.34 to 5.65 μm at a typical working condition. For structure-borne noise transfer, the housing modal and transmission system modal have been analysed. Based on the simulation results, housing thickness around bearing assembly area is increased, and strengthen ribs are added at weak areas. As a result, the amplitude of housing vibration acceleration is reduced. Finally, the transmission noise sound pressure level at 0.3-m distance has decreased by 4.63 dB on average. The presented model-based transmission acoustic analysis work flow is demonstrated workable and effective.